Liquid recovery apparatus, exposure apparatus, exposure method, and device manufacturing method

ABSTRACT

A liquid immersion exposure apparatus includes a projection system having a last optical element, a liquid supply system having a first path through which immersion liquid is supplied to a supply opening, and a liquid removal system having a second path connected to the first path. The liquid removal system removes the immersion liquid from the first path using the second path so that the supply flow path becomes a substantially gas filled space.

RELATED APPLICATIONS

This is a Divisional of U.S. patent application Ser. No. 12/318,574filed Dec. 31, 2008, which in turn is a Divisional of U.S. patentapplication Ser. No. 11/606,935 filed Dec. 1, 2006 (now U.S. Pat. No.7,826,031), which is a Divisional of U.S. patent application Ser. No.11/171,243 filed Jul. 1, 2005 (now U.S. Pat. No. 7,847,916), which is aContinuation-In-Part of International Application No. PCT/JP04/012787filed Aug. 27, 2004. The entire disclosure of each of the priorapplications is incorporated by reference herein in their entireties.The disclosure of each of the following priority applications isincorporated by reference herein in its entirety: Japanese PatentApplication No. 2003-307771 filed Aug. 29, 2003; and Japanese PatentApplication No. 2004-150353 filed May 20, 2004.

BACKGROUND

This invention relates to liquid recovery apparatus, exposure apparatus,exposure methods, and device manufacturing methods, and particularly toexposure apparatus that fill a space between a projection optical systemand a substrate with liquid and expose a pattern onto a substrate viathe projection optical system and the liquid, and device manufacturingmethods using the exposure apparatus.

Semiconductor devices and liquid crystal display devices aremanufactured by a so-called photolithographic method that transfers apattern formed on a mask onto a photosensitive substrate. An exposureapparatus that is used in this photolithographic method is provided witha mask stage that supports a mask, and a substrate stage that supports asubstrate. The exposure apparatus transfers a mask pattern onto asubstrate via a projection optical system while synchronously moving themask stage and the substrate stage. Recently, higher resolution of theprojection optical system is demanded to obtain higher integration of adevice pattern. The resolution of the projection optical systemincreases as an exposure wavelength that is used becomes shorter and anumerical aperture of the projection optical system becomes larger.Because of this, the exposure wavelength that is used in exposureapparatus has become shortened over the years, and the numericalaperture of projection optical systems has increased. Furthermore,although an exposure wavelength of 248 nm of a KrF excimer laser iscurrently the mainstream, an exposure wavelength of 193 nm of an ArFexcimer laser also has been put into practice. When performing exposure,a depth of focus (DOF) also becomes important in addition to theresolution. The resolution R and the depth of focus δ can be expressedby the following equations.

R=k ₁·λ/NA  (1)

δ=±k ₂·λ/NA²  (2)

Here, λ is an exposure wavelength, NA is a numerical aperture of theprojection optical system, and k₁, k₂ are process coefficients.According to equations (1) and (2), in order to increase the resolutionR, by shortening the exposure wavelength λ and increasing the numericalaperture NA, it is understood that the depth of focus δ becomesnarrower.

When the depth of focus δ becomes too narrow, it is difficult to match asubstrate surface with an image plane of the projection optical system,and there is a possibility that a focus margin may become insufficientat the time of an exposure operation. Therefore, a liquid immersionmethod has been proposed, as disclosed in, for example, WO99/49504, as amethod that substantially shortens an exposure wavelength and broadensthe depth of focus. This liquid immersion method fills the space betweena lower surface of the projection optical system and a substrate surfacewith liquid such as water, an organic solvent, or the like, and improvesthe resolution by taking advantage of the fact that the wavelength ofthe exposure light in liquid becomes 1/n (n is normally approximately1.2-1.6 depending on the index of refraction of the liquid) as comparedto the wavelength in air, and increases the depth of focus byapproximately n-times.

Meanwhile, the exposure apparatus disclosed in the above-mentionedreference has a structure in which a liquid immersion region is formedon a substrate by supplying and recovering liquid using a liquid supplymechanism and a liquid recovery mechanism. However, when the drive ofthe liquid recovery mechanism stops due to an abnormality of a powersource, such as a power outage, etc., the liquid remaining on thesubstrate leaks or splashes to an outside of the substrate stage.Therefore, the liquid gets on mechanical parts near the substrate stage,and problems occur such as oxidation, failure, etc.

SUMMARY

One object of some embodiments of this invention is to provide a liquidrecovery apparatus, and an exposure apparatus, an exposure method, and amethod of manufacturing a device using the exposure apparatus, that cansuppress liquid from flowing out and/or splashing, even when a powersource abnormality occurs due to a power outage, for example.

An exposure apparatus that incorporates one or more aspects of theinvention includes a space between a projection optical system and asubstrate that is filled with liquid, and exposes the substrate byprojecting an image of a pattern onto the substrate via the projectionoptical system and the liquid.

According to one aspect, the exposure apparatus includes a liquidrecovery mechanism having a drive portion that is driven by powersupplied from a first power source, and a second power source differentfrom the first power source. When the first power source stops supplyingpower, a supply of power for the drive portion is switched to the secondpower source.

According to another aspect, the exposure apparatus includes a liquidsupply mechanism that supplies liquid, wherein the liquid supplymechanism includes a discharging mechanism that discharges liquid storedin a liquid supply flow path after power supply is stopped.

According to another aspect, the exposure apparatus includes a liquidsupply mechanism having a liquid supply flow path that supplies theliquid, wherein the liquid supply mechanism includes a cut-off portionthat cuts off the liquid supply flow path at the time of an abnormality.

According to another aspect, the exposure apparatus includes a liquidsupply mechanism that supplies liquid, wherein the liquid supplymechanism includes a sensor that detects liquid that remains in a liquidsupply flow path when power supply is stopped.

An exposure apparatus that incorporates one or more aspects of theinvention exposes an image of a pattern onto a substrate via aprojection optical system and includes a liquid recovery mechanism thatrecovers liquid supplied to the substrate and that is supplied withpower from a first power source. According to one aspect, the exposureapparatus also includes a second power source that supplies power to theliquid recovery mechanism at least when the first power source isabnormal. According to another aspect, the exposure apparatus includes aliquid supply mechanism having a supply path that supplies liquidbetween the projection optical system and the substrate, wherein asuction portion having a suction path that draws the liquid is disposedin the liquid supply mechanism.

Another aspect of the invention relates to a liquid recovery devicehaving a liquid recovery mechanism that recovers liquid supplied to asubstrate and that is supplied with power from a first power source. Theliquid recovery device includes a second power source that suppliespower to the liquid recovery mechanism at least when the first powersource is abnormal.

Another aspect of the invention relates to an exposure method in whichliquid is supplied between a projection optical system and a substrate,and a pattern is exposed onto the substrate via the projection opticalsystem and the liquid. According to one aspect, the method includes thesteps of: recovering the liquid by a liquid recovery mechanism suppliedwith power from a first power source; and recovering the liquid by theliquid recovery mechanism supplied with power from a second power sourcedifferent from the first power source at least when the first powersource is abnormal. According to another aspect, the method includes thestep of drawing the liquid from the liquid supply mechanism in responseto a processing state of an exposure process.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings of exemplary embodiments in which like reference numeralsdesignate like elements, and in which:

FIG. 1 is a schematic structural view showing an exposure apparatus ofone embodiment;

FIG. 2 is a diagram showing a positional relationship between a leadingend portion of a projection optical system, a liquid supply mechanism,and a liquid recovery mechanism;

FIG. 3 is a diagram showing an exemplary arrangement of supply nozzlesand recovery nozzles;

FIG. 4 is a schematic perspective view of a substrate stage;

FIG. 5 is an enlarged cross-sectional view showing a main portion of anembodiment of a second liquid recovery mechanism;

FIG. 6 is a schematic structural view showing another embodiment of anexposure apparatus;

FIGS. 7A, 7B, and 7C are schematic views showing an example of anexposure operation;

FIGS. 8A and 8B are schematic views showing movement of liquid of asupply path;

FIGS. 9A and 9B are schematic views showing movement of liquid of asupply path; and

FIG. 10 is a flowchart showing an example of a process of manufacturinga semiconductor device.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

An exposure apparatus according to a first aspect of this invention hasa space between a projection optical system and a substrate that isfilled with liquid, and exposes the substrate by projecting an image ofa pattern onto the substrate via the projection optical system and theliquid. The exposure apparatus includes a liquid recovery mechanismhaving a drive portion that is driven by power supplied from a firstpower source, and a second power source different from the first powersource. When the first power source stops supplying power, a powersupply for the drive portion is switched to the second power source.When the liquid recovery mechanism is driven by the power that issupplied from the first power source, even when there is an abnormalityin the first power source, the power supply for the liquid recoverymechanism is switched to the second power source. Accordingly, liquidthat remains on the substrate is recovered by the liquid recoverymechanism that is driven by the power that is supplied from the secondpower source, and thus the liquid is not left on the substrate.Therefore, out-flow of the liquid can be suppressed, and problems thatoccur due to out-flow of the liquid can be suppressed.

An exposure apparatus according to a second aspect of this inventionexposes an image of a pattern image onto a substrate by a projectionoptical system, and includes a liquid recovery mechanism supplied withpower from a first power source and that recovers liquid supplied to thesubstrate. The apparatus also includes a second power source thatsupplies power to the liquid recovery mechanism at least when the firstpower source is abnormal. When there is an abnormality in the firstpower source, the second power source supplies the power to the liquidrecovery mechanism. Thus, even when there is an abnormality in the firstpower source, the liquid supplied to the substrate can be recovered, anddeterioration of mechanical parts and electrical parts in the vicinityof the substrate can be suppressed.

An exposure apparatus according to a third aspect of this invention hasa space between a projection optical system and a substrate that isfilled with liquid, and exposes the substrate by projecting an image ofa pattern onto the substrate via the projection optical system and theliquid. This exposure apparatus includes a liquid supply mechanism thatsupplies liquid, and the liquid supply mechanism is provided with adischarging mechanism that discharges liquid stored in a liquid supplyflow path after power supply is stopped. When the power supply isstopped, the discharging mechanism discharges (removes) liquid stored inthe liquid supply flow path. Thus, if the discharged liquid isrecovered, a problem in which the liquid leaks onto the substrate fromthe liquid supply mechanism can be suppressed.

An exposure apparatus according to a fourth aspect of this invention hasa space between a projection optical system and a substrate that isfilled with liquid, and exposes the substrate by projecting an image ofa pattern onto the substrate via the projection optical system and theliquid. The exposure apparatus includes a liquid supply mechanismprovided with a liquid supply flow path that supplies the liquid. Inaddition, the liquid supply mechanism is provided with a cut-off portionthat cuts off the liquid supply flow path at the time of an abnormality.Thus, even when there is an abnormality, deterioration of mechanicalparts and electrical parts in the vicinity of the substrate due to theliquid can be suppressed.

An exposure apparatus according to a fifth aspect of this invention hasa space between a projection optical system and a substrate that isfilled with liquid, and exposes the substrate by projecting an image ofa pattern onto the substrate via the projection optical system and theliquid. The exposure apparatus includes a liquid supply mechanism thatsupplies liquid, and the liquid supply mechanism is provided with asensor that detects liquid that remains in a liquid supply flow pathwhen power supply is stopped. When power supply is stopped, the sensorconfirms whether liquid exists in the liquid supply flow path. Thus, ifthe sensor confirms that the liquid exists, by recovering the liquid, aproblem in which the liquid leaks onto the substrate from the liquidsupply mechanism can be suppressed.

A liquid recovery device according to an aspect of this inventionincludes a liquid recovery mechanism supplied with power from a firstpower source and recovers liquid supplied to the substrate. The liquidrecovery device also includes a second power source that supplies powerto the liquid recovery mechanism at least when the first power source isabnormal. Thus, even when there is an abnormality in the first powersource, the liquid supplied to the substrate can be recovered, anddeterioration of mechanical parts and electrical parts in the vicinityof the substrate can be suppressed.

An exposure method according to an aspect of this invention suppliesliquid between a projection optical system and a substrate, and exposesa pattern onto the substrate via the projection optical system and theliquid. The method includes the steps of recovering the liquid by usinga liquid recovery mechanism supplied with power from a first powersource, and recovering the liquid using the liquid recovery mechanismsupplied with power from a second power source different from the firstpower source at least when the first power source is abnormal. Whenthere is an abnormality in the first power source, the second powersource supplies the power to the liquid recovery mechanism. Thus, evenwhen there is an abnormality in the first power source, the liquidsupplied to the substrate can be recovered, and deterioration ofmechanical parts and electrical parts in the vicinity of the substratecan be suppressed.

An exposure apparatus according to another aspect of this inventionexposes an image of a pattern onto a substrate using a projectionoptical system, and includes a liquid supply mechanism having a supplypath that supplies liquid between the projection optical system and thesubstrate. In addition, a suction portion having a suction path thatdraws the liquid is disposed in the liquid supply mechanism. The suctionportion draws the liquid of the liquid supply mechanism via the suctionpath. Thus, even when there is an abnormality in the liquid supplymechanism and/or the main body of the exposure apparatus, a problem inwhich the liquid leaks from the liquid supply mechanism can besuppressed. Because of this, deterioration of mechanical parts andelectrical parts in the vicinity of the substrate can be avoided.

An exposure method according to another aspect of this invention uses aliquid supply mechanism to supply liquid between a projection opticalsystem and a substrate and exposes an image of a pattern onto thesubstrate using the projection optical system. The method includes thestep of drawing the liquid from the liquid supply mechanism in responseto a processing state of the exposure. Thus, when there is anabnormality in the liquid supply mechanism, a problem in whichdeterioration of mechanical parts and electrical parts in the vicinityof the substrate can be suppressed.

Embodiments implementing one or more aspects of the invention are nowdescribed. However, the invention is not limited to these embodiments.

According to one or more aspects of this invention, when an abnormalitysuch as a power outage occurs, out-flow of the liquid can be suppressed,and occurrence of problems due to out-flow of the liquid can besuppressed. Furthermore, when liquid does not need to be supplied, aproblem in which the liquid leaks from the liquid supply mechanism canbe suppressed. Therefore, a pattern can be accurately transferred ontothe substrate, and a device with high pattern precision can bemanufactured.

FIG. 1 is a schematic structural view showing an exposure apparatus ofone embodiment. In FIG. 1, an exposure apparatus EX includes a maskstage MST that supports a mask M, a substrate stage PST that supports asubstrate P, an illumination optical system IL that illuminates the maskM supported by the mask stage MST with exposure light EL, a projectionoptical system PL that projects and exposes an image of a pattern of themask M illuminated by the exposure light EL onto the substrate Psupported by the substrate stage PST, and a controller CONT thatcontrols the overall operation of the entire exposure apparatus EX.Additionally, a chamber shown by dotted lines of FIG. 1 stores at leastthe mask stage MST, the substrate stage PST, the illumination opticalsystem IL, and the projection optical system PL, and predeterminedhumidity and temperature are maintained in the chamber. The entireexposure apparatus EX is driven by power supplied from a commercialpower source (first power source) 100 such as a power company locatedoutside of the chamber.

The exposure apparatus EX of this embodiment is a liquid immersionexposure apparatus, in which a liquid immersion method is used tosubstantially widen the depth of focus as well as improve the resolutionby substantially shortening the exposure wavelength, and includes aliquid supply mechanism 10 that supplies liquid 1 onto the substrate Pand a liquid recovery mechanism 20 that recovers the liquid 1 from thesubstrate P. The exposure apparatus EX uses the liquid 1 supplied fromthe liquid supply mechanism 10 to form a liquid immersion region AR2 ata part of the substrate P that includes a projection region AR1 of theprojection optical system PL. In the exposure apparatus EX, the spacebetween an end surface 2 a of an optical element 2 located at a leadingend portion (end portion) of the projection optical system PL and asurface of the substrate P is filled with the liquid 1, and exposureapparatus EX exposes the substrate P by projecting an image of thepattern of the mask M onto the substrate P through the projectionoptical systems PL and through the liquid 1 between the projectionoptical system PL and the substrate P.

In this embodiment, an explanation is given with an example using ascanning type exposure apparatus (a so-called scanning stepper), as theexposure apparatus EX, that exposes a pattern formed on the mask M ontothe substrate P while synchronously moving the mask M and substrate P inmutually different directions (opposite directions) in the scanningdirection. In the following description, the direction that matches anoptical axis AX of the projection optical system PL is designated as a Zaxis direction, a direction (scanning direction) of the synchronousmovement by the mask M and the substrate P in a plane perpendicular tothe Z axis direction is designated as an X axis direction, and thedirection (non-scanning direction) perpendicular to the Z axis directionand perpendicular to the X axis direction is designated as a Y axisdirection. Furthermore, the rotation (inclination) directions about theX axis, the Y axis, and the Z axis are designated as θX, θY, and θZdirections, respectively. The term “substrate” includes anything onwhich a photoresist, which is a photosensitive material, is applied, andthe term “mask” includes a reticle on which a device pattern to bereduced and projected onto the substrate is formed.

The illumination optical system IL illuminates the mask M supported bythe mask stage MST with the exposure light EL, and has an exposure lightsource that emits the exposure light EL, an optical integrator thatuniformizes the intensity of the exposure light EL emitted from theexposure light source, a condenser lens that collects the exposure lightEL from the optical integrator, a relay lens system, a variable fieldstop that sets an illumination region on the mask M by the exposurelight EL in a slit shape, etc. The predetermined illumination region onthe mask M is illuminated with the exposure light EL having a uniformintensity distribution by the illumination optical system IL. Forexample, the exposure light EL emitted from the exposure light sourcemay be a bright line (g-line, h-line, i-line) in the ultraviolet regionemitted from a mercury lamp, far ultraviolet light (DUV light), such asa KrF excimer laser light (wavelength: 248 nm), and vacuum ultravioletlight (VUV light), such as an ArF excimer laser light (wavelength: 193nm) and an F₂ laser light (wavelength: 157 nm). In this embodiment, theArF excimer laser is used.

In this embodiment, distilled water is used as the liquid 1 that issupplied from the liquid supply mechanism 10. The distilled water cantransmit not only the ArF excimer laser light but also, for example, thebright lines (g-line, h-line, i-line) in the ultraviolet region emittedfrom a mercury lamp, and far ultraviolet light (DUV light), such as KrFexcimer laser light (wavelength: 248 nm).

The mask stage MST supports the mask M and can be two-dimensionallymoved within a plane perpendicular to the optical axis AX of theprojection optical system PL, that is, within the XY plane and can bemicro-rotated in the θZ direction. The mask stage MST is driven by amask stage drive device MSTD such as a linear motor. The mask stagedrive device MSTD is controlled by the controller CONT. The position androtation angle of the mask M in the two-dimensional direction on themask stage MST are measured by an undepicted laser interferometer inreal time, and the measurement result is output to the controller CONT.The controller CONT positions the mask M that is supported on the maskstage MST by driving the mask stage drive device MSTD based on themeasurement result of the laser interferometer.

The projection optical system PL projects and exposes a pattern of themask M onto the substrate P at a predetermined projection magnificationβ, and is constituted by a plurality of optical elements (lenses, etc.)that are supported by a lens barrel PK. In this embodiment, theprojection optical system PL is a reduction inversion system, in whichthe projection magnification β is ¼ or ⅕, for example. Alternatively,the projection optical system PL can be either a unity system or amagnifying system. Furthermore, the projection optical system PL can benot only a dioptric system but also a catadioptric system or areflective system, and can form either an inverted image or an erectimage. In addition, on the front end side (substrate P side) of theprojection optical system PL of this embodiment, the optical element 2extends from the lens barrel PK, and is detachably (replaceably)provided to the lens barrel PK. The substrate stage PST supports thesubstrate P and is provided with a Z stage (substrate holder) 51 thatholds the substrate P via a substrate holder, an XY stage 52 thatsupports the Z stage 51, and a base 53 that supports the XY stage 52.The substrate stage PST is driven by the substrate stage drive devicePSTD such as a linear motor. The substrate stage drive device PSTD iscontrolled by the controller CONT. By driving the Z stage 51, theposition (focus position) of the substrate P in the Z axis directionsupported by the Z stage 51 and the position in the θX and θY directionsare controlled. Furthermore, by driving the XY stage 52, the position ofthe substrate P in the XY directions (position in the directionsubstantially parallel to an image plane of the projection opticalsystem PL) is controlled. That is, by controlling the focus position andthe inclination angle, the Z stage 51 matches the surface of thesubstrate P with the image plane of the projection optical system PL byan auto focus method and an auto leveling method. The XY stage 52positions the substrate P in the X axis direction and in the Y axisdirection. Furthermore, the Z stage and the XY stage can be integrated.

Moving mirrors 45 are arranged on the substrate stage PST. Furthermore,laser interferometers 46 are arranged at positions opposing the movingmirrors 45. The position of the substrate P on the substrate stage PSTin the two-dimensional directions and the rotation angle about the axesare measured by the laser interferometers 46 in real time, and themeasurement results are output to the controller CONT. The controllerCONT positions the substrate P, which is supported on the substratestage PST, by driving the substrate stage drive device PSTD based on themeasurement result of the laser interferometers 46.

Furthermore, on the substrate stage PST (Z stage 51), an auxiliary plate43 is arranged so as to surround the substrate P. The auxiliary plate 43is located substantially in the same plane as the surface of thesubstrate P that is held on the Z stage (substrate holder). When theedge region of the substrate P is exposed, the liquid 1 can be heldunder the projection optical system PL by the auxiliary plate 43.

Furthermore, on the Z stage 51, outside the auxiliary plate 43, arecovery port 61 of a second liquid recovery mechanism 60 is arranged,which recovers the liquid 1 that flows to the outside of the substrateP. The recovery port 61 is an annular groove portion that is formed soas to surround the auxiliary plate 43. A liquid absorption member 62formed of a sponge member, a porous body, etc. is arranged therein.

FIG. 2 is an enlarged diagram showing the liquid supply mechanism 10,the liquid recovery mechanism 20, and the vicinity of the leading endportion of the projection optical system PL. The liquid supply mechanism10 supplies the liquid 1 between the projection optical system PL andthe substrate P, and is provided with a liquid supply portion 11 thatcan eject the liquid 1, and a supply nozzle 14 that is connected to theliquid supply portion 11 via a supply tube 15 and supplies the liquidejected from the liquid supply portion 11 onto the substrate P. Thesupply nozzle 14 is arranged near the surface of the substrate P. Theliquid supply portion 11 is provided with a tank for storing the liquid1, a pressure pump, etc. The liquid 1 is supplied onto the substrate Pvia the supply tube 15 and the supply nozzle 14. The liquid supplyoperation of the liquid supply portion 11 is controlled by thecontroller CONT, and the controller CONT can control the liquid supplyamount per unit time onto the substrate P by the liquid supply portion11. It is also acceptable to use a factory-wide liquid supply system,without providing the dedicated liquid supply portion 11 on the exposureapparatus.

In the supply tube 15, a valve (cut-off portion) 13 is arranged, whichopens and closes a flow path of the supply tube 15. The open/closeoperation of the valve 13 is controlled by the controller CONT. Inaddition, the valve 13 of this embodiment is a so-called normally closedtype that mechanically cuts off the liquid supply flow path of thesupply tube 15 when the drive source (commercial power source 100) ofthe exposure apparatus EX (and of the controller CONT) stops due to, forexample, a power outage, etc.

Additionally, one end portion of a suction tube 18 is connected (joined)between the valve 13 and the supply nozzle 14 in the supply tube 15, andanother end portion of the suction tube 18 is connected to a thirdliquid recovery mechanism 17. In the suction tube 18, a valve 16 isarranged which opens and closes a flow path of the suction tube 18. Theone end portion of the suction tube 18 joins the liquid supply flow pathof the supply tube 15 at a position immediately downstream of the valve13.

The liquid recovery mechanism 20 recovers the liquid 1 on the substrateP that has been supplied by the liquid supply mechanism 10 and isprovided with a recovery nozzle 21 arranged in the vicinity of thesurface of the substrate P, and a vacuum system 25 connected to therecovery nozzle 21 via a recovery tube 24. The vacuum system 25 isconstituted by a vacuum pump, and the operation is controlled by thecontroller CONT. As the vacuum system 25 is driven, the liquid 1 on thesubstrate P is recovered via the recovery nozzle 21 along with ambientgas (air). In addition, a vacuum system for the factory in which theexposure apparatus EX is arranged may be used as the vacuum system 25,without providing a dedicated vacuum pump in the exposure apparatus.

A gas-liquid separator 22 that separates the liquid 1 and the gas drawnby the recovery nozzle 21 is provided in the recovery tube 24. Asdescribed above, the liquid 1 on the substrate P and ambient gas arerecovered from the recovery nozzle 21. The gas-liquid separator 22separates the liquid 1 and the gas recovered by the recovery nozzle 21.For the gas-liquid separator 22, for example, a gravity separationmethod that separates the liquid from the gas by communicating therecovered liquid and gas in a tube member having a plurality of holesand dropping the liquid through the holes, using gravity, or acentrifugal separation method that separates the recovered liquid andgas using centrifugal force, may be used. The vacuum system 25 draws thegas separated by the gas-liquid separator 22.

A dryer 23 that dries the gas separated by the gas-liquid separator 22is provided in the recovery tube 24, between the vacuum system 25 andthe gas-liquid separator 22. Even if liquid particles are mixed in thegas separated by the gas-liquid separator 22, occurrence of trouble suchas failure of the vacuum system 25 due to entry of the liquid particlescan be suppressed by drying the gas using the dryer 23 and by causingthe dried gas to flow into the vacuum system 25. For the dryer 23, amethod for removing the liquid particles by cooling the gas supplied bythe gas-liquid separator 22 (gas in which the liquid particles aremixed) to or below the dew point of the liquid, or a method for removingthe liquid particles by heating the gas to or above the boiling point ofthe liquid may be used.

Meanwhile, the liquid 1 separated by the gas-liquid separator 22 isrecovered in a liquid recovery portion 28 via a second recovery tube 26.The liquid recovery portion 28 is provided with a tank, etc. that storesthe recovered liquid 1. The liquid 1 recovered by the liquid recoveryportion 28 is, for example, discarded or recycled and returned to theliquid supply portion 11, etc. after being cleaned.

A back-up power source 102 that supplies power to the drive portion ofthe liquid recovery mechanism 20 when the commercial power source 100stops supplying power, is connected to the liquid recovery mechanism 20.Even when a power source trouble occurs such as power outage, voltagefluctuation, etc., the back-up power source 102 (in this embodiment, aUPS: Uninterruptible Power System) supplies stabilized power from abattery arranged inside the device. In this embodiment, in order toavoid the effects of heat from the back-up power source 102, the back-uppower source 102 is arranged outside of the chamber. In this embodiment,when the commercial power source 100 stops supplying power, the back-uppower source 102 supplies power to a power drive portion of the vacuumsystem 25, a power drive portion of the separator 22, and a power driveportion of the dryer 23, of the liquid recovery mechanism 20.Furthermore, the back-up power source 102 can supply power to therespective power drive portions along with the commercial power source100, and can supply power to the respective power drive portions inresponse to voltage fluctuations of the commercial power source 100.Furthermore, the back-up power source 102 can be arranged within thechamber.

A liquid sensor 81 that detects whether liquid 1 exists in the supplytube 15 (whether liquid 1 flows through the supply tube 15) is arrangedin the supply tube 15. The liquid sensor 81 is arranged in the vicinityof the supply nozzle 14 of the supply tube 15. Furthermore, a liquidsensor 82 that detects whether liquid 1 exists in the recovery tube 24(whether the liquid 1 flows through the recovery tube 24) is arranged inthe recovery tube 24. The liquid sensor 82 is arranged in the vicinityof the recovery nozzle 21 of the recovery tube 24. In this embodiment,each liquid sensor 81 (82) optically detects the liquid 1. For example,by forming the supply tube 15 (and the recovery tube 24) from atransparent member and mounting the liquid sensor 81 (82) outside of thesupply tube 15 (and the recovery tube 24), the liquid sensor 81 (82) candetect whether the liquid 1 flows through the supply tube 15 (and therecovery tube 24) formed of the transparent member. Furthermore, theliquid sensors 81, 82 are driven by power that is supplied from thecommercial power source 100, but when the commercial power source 100stops supplying power, it is driven by power that is supplied by theback-up power source 102.

Additionally, a memory device MRY that stores various informationrelating to liquid immersion exposure processing, including informationconcerning the liquid 1, is arranged in the liquid recovery mechanism20. As described later, when the commercial power source 100 stopssupplying power, the liquid recovery mechanism 20 is driven based on thememory information of the memory device MRY.

FIG. 3 is a plan view showing the positional relationship between theliquid supply mechanism 10, the liquid recovery mechanism 20, and theprojection region AR1 of the projection optical system PL. Theprojection region AR1 of the projection optical system PL is arectangular shape (slit shape) that is elongated in the Y axisdirection. Three supply nozzles 14A-14C are arranged on the +X side, andtwo recovery nozzles 21A and 21B are arranged on the −X side, so as tosandwich the projection region AR1 in the X axis direction. Furthermore,the supply nozzles 14A-14C are connected to the liquid supply portion 11via the supply tube 15, and the recovery nozzles 21A and 21B areconnected to the vacuum system 25 via the recovery tube 24. In addition,supply nozzles 14A′-14C′ and recovery nozzles 21A′ and 21B′ are arrangedso as to have the positional relationship in which the supply nozzles14A-14C and the recovery nozzles 21A and 21B are rotated bysubstantially 180°. The supply nozzles 14A-14C and the recovery nozzles21A′ and 21B′ are alternately arranged in the Y axis direction, and thesupply nozzles 14A′-14C′ and the recovery nozzles 21A and 21B arealternately arranged in the Y axis direction. The supply nozzles14A′-14C′ are connected to the liquid supply portion 11 via the supplytube 15′, and the recovery nozzles 21A′ and 21B′ are connected to thevacuum system 25 via a recovery tube 24′. In the same manner as thesupply tube 15, a valve 13′ is provided in the supply tube 15′, and thesupply tube 15′ is connected to a third liquid recovery mechanism 17′ bya suction tube 18′ having a valve 16′ therein. Furthermore, in the samemanner as the suction tube 24, a gas-liquid separator 22′ and a dryer23′ are provided in the recovery tube 24′.

The configuration of the above-described nozzles is not particularlylimited. For example, the supply and recovery of the liquid 1 may beperformed by two pairs of nozzles provided at the long sides of theprojection region AR1. In this case, the supply nozzles and the recoverynozzles may be horizontally arranged so that the liquid 1 can besupplied and recovered in either the +X direction or the −X direction.

FIG. 4 is a perspective view of the Z stage 51. FIG. 5 is an enlargedcross-sectional view showing a main portion of a second liquid recoverymechanism 60 arranged on the Z stage 51. The second liquid recoverymechanism 60 recovers the liquid 1 that flows to the outside of thesubstrate P and includes a recovery port 61 that is annularly formed soas to surround the auxiliary plate 43 on the Z stage (substrate holder)51 and a liquid absorption member 62 arranged in the recovery port 61and formed of a porous body such as a sponge member, a porous ceramic,etc. The liquid absorption member 62 is an annular member having apredetermined width and can hold a predetermined amount of the liquid 1.The liquid absorption member 62 that is arranged so as to surround theouter circumference of the auxiliary plate 43 at a predetermined spacingfunctions to absorb (recover) the liquid 1 that cannot be recovered bythe liquid recovery mechanism 20 alone and that flows to the outside ofthe auxiliary plate 43. A flow path 63 that communicates with therecovery port 61 is formed within the Z stage 51, and the bottom portionof the liquid absorption member 62 arranged in the recovery port 61communicates with the flow path 63. Furthermore, a plurality of liquidrecovery holes 64 are arranged between the substrate P and the auxiliaryplate 43 on the Z stage 51. The liquid recovery holes 64 are connectedto the flow path 63.

A plurality of protrusions 65 that support the rear surface of thesubstrate P are arranged on the top surface of the Z stage (substrateholder) 51 that holds the substrate P. Adsorption holes 66 that adsorband hold the substrate P are arranged in the protrusions 65,respectively. The respective adsorption holes 66 are connected to a flowpath 67 formed inside the Z stage 51.

The flow path 63 connected to the recovery port 61 and the liquidrecovery holes 64 is connected to one end portion of a tube path 68arranged outside of the Z stage 51. Meanwhile, the other end portion ofthe tube path 68 is connected to a vacuum system 70 including a vacuumpump. A gas-liquid separator 71 is arranged in the tube path 68. A dryer72 is arranged between the gas-liquid separator 71 and the vacuum system70. The liquid 1 from the recovery port 61 is recovered along with theambient gas by driving the vacuum system 70. A gas that is separated bythe gas-liquid separator 71 and dried by the dryer 72 flows into thevacuum system 70. Meanwhile, the liquid 1 separated by the gas-liquidseparator 71 flows into a liquid recovery portion 73 provided with atank, etc. that can store the liquid 1. In addition, the liquid 1recovered by the liquid recovery portion 73 is, for example, discardedor recycled and returned to the liquid supply portion 11, etc. afterbeing cleaned.

Furthermore, the flow path 67 connected to the adsorption holes 66 isconnected to one end portion of a tube path 69 arranged outside of the Zstage 51. Meanwhile, the other end portion of the tube path 69 isconnected to a vacuum system 74 including a vacuum pump arranged outsideof the Z stage 51. By driving the vacuum system 74, the substrate Psupported by the protrusions 65 is adsorbed and held by the adsorptionholes 66. A gas-liquid separator 75 is arranged in the tube path 69, anda dryer 76 is arranged between the gas-liquid separator 75 and thevacuum system 74. Furthermore, the liquid recovery portion 73 providedwith a tank, etc. that can store the liquid 1 is connected to thegas-liquid separator 75. Even if the liquid 1 enters from between thesubstrate P and the auxiliary plate 43 and flows to the rear surfaceside of the substrate P, the liquid can be recovered with the ambientgas from the adsorption holes 66.

In addition, in FIG. 4, on the +X side end portion of the Z stage 51, amoving mirror 45X is arranged which extends in the Y axis direction, andon the Y side end portion, a moving mirror 45Y is arranged which extendsin the X axis direction. Laser interferometers detect the position ofthe substrate stage PST in the X axis direction and in the Y axisdirection by irradiating laser beams onto the moving mirrors 45X, 45Y.

The following explains a procedure for exposing a pattern of the mask Monto the substrate P by using the above-described exposure apparatus EX.

After the mask M is loaded onto the mask stage MST and the substrate Pis loaded onto the substrate stage PST, the controller CONT drives theliquid supply portion 11 of the liquid supply mechanism 10 and suppliesa predetermined amount of the liquid 1 per unit time onto the substrateP via the supply tube 15 and the supply nozzle 14. At this time, theliquid supply flow path of the supply tube 15 is opened, and the flowpath of the suction tube 18 is closed by the valve 16. In addition, thecontroller CONT drives the vacuum system 25 of the liquid recoverymechanism 20 in accordance with the supply of the liquid 1 by the liquidsupply mechanism 10, and recovers a predetermined amount of the liquid 1per unit time via the recovery nozzle 21 and the recovery tube 24. As aresult, the liquid immersion region AR2 of the liquid 1 is formedbetween the optical element 2 at the front end portion of the projectionoptical system PL and the substrate P. At this time, the entire exposureapparatus EX is driven by power that is supplied by the commercial powersource 100. Here, in order to form the liquid immersion region AR2, thecontroller CONT controls the liquid supply mechanism 10 and the liquidrecovery mechanism 20 so that the amount of the liquid supplied to thesubstrate P and the amount of liquid recovered from the substrate Pbecome substantially the same amount. In addition, the controller CONTperforms control so that the exposure apparatus EX illuminates the maskM with the exposure light EL by the illumination optical system IL andprojects an image of the pattern of the mask M onto the substrate P viathe projection optical system PL and the liquid 1.

At the time of scanning exposure, a portion of a pattern image on themask M is projected onto the projection region AR1. With respect to theprojection optical system PL, synchronous to the mask M moving in the −Xdirection (or +X direction) at a velocity V, the substrate P moves inthe +X direction (or −X direction) at a velocity β·V (β is a projectionmagnification) via the substrate stage PST. Then, after exposure iscompleted in one shot region, the next shot region is moved to ascanning start position by stepping of the substrate P. Hereafter, theexposure processing for each shot region is sequentially performed by astep-and-scan method. This embodiment is set so that the liquid 1 flowsin a direction parallel to the direction of movement of the substrate P,that is, in the same direction as the direction of the movement of thesubstrate P. In other words, when performing the scanning exposure bymoving the substrate P in the scanning direction (−X direction) shown byan arrow Xa (see FIG. 3), the supply and recovery of the liquid 1 by theliquid supply mechanism 10 and the liquid recovery mechanism 20 areperformed by using the supply tube 15, the supply nozzles 14A-14C, therecovery tube 24, and the recovery nozzles 21A and 21B. That is, whenthe substrate P moves in the −X direction, the liquid 1 is suppliedbetween the projection optical system PL and substrate P by the supplynozzle 14 (14A-14C), the liquid 1 on the substrate P is recovered by therecovery nozzle 21 (21A and 21B) along with the ambient gas, and theliquid 1 flows in the −X direction so as to fill the space between theoptical element 2 at the front end portion of the projection opticalsystem PL and the substrate P. Meanwhile, when performing the scanningexposure by moving the substrate P in the scanning direction (+Xdirection) shown by an arrow Xb (see FIG. 3), the supply and recovery ofthe liquid 1 by the liquid supply mechanism 10 and the liquid recoverymechanism 20 are performed by using the supply tube 15′, the supplynozzles 14A′-14C′, the recovery tube 24′, and the recovery nozzles 21A′and 21B′. That is, when the substrate P moves in the +X direction, theliquid 1 is supplied between the projection optical system PL andsubstrate P by the supply nozzle 14′ (14A′-14C′), the liquid 1 on thesubstrate P is recovered by the recovery nozzle 21′ (21A′ and 21B′)along with the ambient gas, and the liquid 1 flows in the +X directionso as to fill the space between the optical element 2 at the front endportion of the projection optical system PL and the substrate P. In thiscase, the liquid 1 that is supplied via the supply nozzle 14 flows as ifit were drawn to the space between the optical element 2 and thesubstrate P in accordance with the movement of the substrate P in the −Xdirection. Therefore, even if the supply energy of the liquid supplymechanism 10 (liquid supply portion 11) is small, the liquid 1 can beeasily supplied between the optical element 2 and the substrate P. Then,by switching the direction of the flow of the liquid 1 according to thescanning direction, when the substrate P is scanned in either the +Xdirection or the −X direction, the space between the optical element 2and the substrate P can be filled with the liquid 1. Therefore, a highresolution and a wide depth of focus can be obtained.

While the shot region near the center of the substrate P is exposed, theliquid 1 supplied from the liquid supply mechanism 10 is recovered bythe liquid recovery mechanism 20. Meanwhile, as shown in FIG. 5, whenthe liquid immersion region AR2 is in the vicinity of the edge region ofthe substrate P due to exposure-processing the edge region of thesubstrate P, the liquid 1 can be maintained between the projectionoptical system PL and the substrate P by the auxiliary plate 43, butthere is a case in which part of the liquid 1 flows to the outside ofthe auxiliary plate 43. The liquid 1 thus discharged is recovered by therecovery port 61 in which the liquid absorption member 62 is arranged.Here, the controller CONT starts an operation of the second liquidrecovery mechanism 60 along with driving the liquid supply mechanism 10and the liquid recovery mechanism 20. Therefore, the liquid 1 recoveredby the recovery port 61 is recovered by suction of the vacuum system 70via the flow path 63 and the tube path 68, along with ambient air.Furthermore, the liquid 1 that has flowed into the gap between thesubstrate P and the auxiliary plate 43 is recovered via the flow path 63and the tube path 68, along with the ambient air, via the liquidrecovery holes 64. At this time, the separator 71 separates the liquid 1and the gas recovered through the recovery port 61 and the recoveryholes 64. The gas separated by the separator 71 flows into the vacuumsystem 70 after being dried by the dryer 72. By doing this, a problemcan be suppressed in which the liquid component flows into the vacuumsystem 70. Meanwhile, the liquid separated by the separator 71 isrecovered by the liquid recovery portion 73.

There may be a case in which the liquid 1 discharged outside of thesubstrate P enters from the gap between the substrate P and theauxiliary plate 43 and reaches the rear surface side of the substrate P.Additionally, there is also a possibility that the liquid 1 that enteredthe rear surface side of the substrate P flows into the adsorption holes66 that adsorb and hold the substrate P. In this case, the adsorptionholes 66 arranged in the Z stage 51 so as to adsorb and hold thesubstrate P are connected to the vacuum system 74 via the flow path 67and the tube path 69. In the tube path 69, the gas-liquid separator 75and the dryer 76 that dries the gas separated by the gas-liquidseparator 75 are arranged. Therefore, even if the liquid 1 enters theadsorption holes 66, a problem can be suppressed in which the liquidcomponent enters the vacuum system 74.

Meanwhile, in the exposure apparatus EX of this embodiment, each powerdrive portion constituting the exposure apparatus EX including theliquid supply mechanism 10, the liquid recovery mechanism 20, and thesecond liquid recovery mechanism 60 is driven by power supplied from thecommercial power source 100. However, when the commercial power source100 stops supplying power, the supply of the power for the drive portionof the liquid recovery mechanism 20 is switched to the back-up powersource 102. The following explains the operation of the exposureapparatus EX when the commercial power source 100 stops supplying power.

When the commercial power source 100 stops supplying power, as describedbefore, the back-up power source 102 continuously supplies power byswitching the power source supply for the liquid recovery mechanism 20to, for example, a built-in battery. After that, the back-up powersource 102 activates a built-in generator, in case the power outagecontinues for many hours, and the power supply for the liquid recoverymechanism 20 is switched from the battery to the generator. At thistime, the back-up power source 102 performs power supply for at leastthe vacuum system 25, the separator 22, and the dryer 23 of the liquidrecovery mechanism 20. By doing this, even if the commercial powersource 100 stops supplying power, the power supply for the liquidrecovery mechanism 20 continues, and the liquid recovery operation bythe liquid recovery mechanism 20 can be maintained. Furthermore, theback-up power source 102 is not limited to the above-mentionedembodiment, and any well-known back-up power source can be used. Inaddition, in this embodiment, a back-up power source device is used asan example of a back-up power source when the commercial power source100 stops supplying power; however, a back-up battery can be used as aback-up power source. When the commercial power source 100 stopssupplying power, the system can be switched to the battery. Furthermore,a private power generator in a factory also can be used as a back-uppower source, and a capacitor also can be used as a back-up powersource.

Furthermore, when the commercial power source 100 stops supplying power,the back-up power source 102 also supplies power to the second liquidrecovery mechanism 60. Specifically, the back-up power source 102supplies power to at least the vacuum system 70, the separator 71, andthe dryer 72 of the second liquid recovery mechanism 60. By doing this,for example, when the commercial power source 100 stops supplying powerin a state in which part of the liquid immersion region AR2 of theliquid 1 is arranged on the auxiliary plate 43, and the liquid 1 flowsto the outside of the substrate P, the second liquid recovery mechanism60 can recover the discharged liquid 1. In addition, when the commercialpower source 100 stops supplying power, the back-up power source 102 canalso supply the power to the vacuum system 74, the separator 75, and thedryer 76. By doing this, when the commercial power source 100 stopssupplying power, adsorption and holding of the substrate P by the Zstage 51 can be maintained. Thus, the position of the substrate P is notshifted with respect to the Z stage 51 due to the power outage.Therefore, after the power recovers, when the exposure operation beginsagain, the restart operation of the exposure processing can be smoothlyperformed.

Meanwhile, when the commercial power source 100 stops supplying power,the normally closed type valve 13 arranged in the supply tube 15 of theliquid supply mechanism 10 is operated, and the liquid supply flow pathof the supply tube 15 is cut off. By doing this, after the commercialpower source 100 stops supplying power, there is no problem caused bythe liquid 1 leaking onto the substrate P from the liquid supplymechanism 10. Furthermore, in this embodiment, when the commercial powersource 100 stops supplying power, the valve 16 of the suction tube 18 ismechanically operated, the flow path of the suction tube 18 is opened,and the back-up power source 102 supplies power to the third liquidrecovery mechanism 17. The third liquid recovery mechanism 17 hassubstantially the same function as the liquid recovery mechanism 20 andthe second liquid recovery mechanism 60 and is provided with a vacuumsystem such as an undepicted suction pump, a dryer, a separator, and aliquid recovery portion. For example, when a suction pump of the thirdliquid recovery mechanism 17 is operated by the power supplied from theback-up power source 102, the liquid 1 stored in the liquid flow path onthe downstream side of the valve 13 in the supply tube 15, and in thesupply nozzle 14, is drawn by the suction pump of the third liquidrecovery mechanism 17 via the suction tube 18. The suction tube 18 isconnected to the liquid supply flow path of the supply tube 15 at aposition immediately on the downstream side of the valve 13, so theliquid 1 stored in the liquid supply flow path between the valve 13 andthe supply nozzle 14 of the supply tube 15 is drawn and recovered. Bydoing this, after the commercial power source 100 stops supplying power,a problem can be further reliably suppressed in which the liquid 1 leaksonto the substrate P from the liquid supply mechanism 10, and occurrenceof a problem can be suppressed in which the liquid 1 splashes onto thesubstrate stage PST and in the vicinity of the substrate stage PST.

Furthermore, after the commercial power source 100 stops supplyingpower, the back-up power source 102 continues to supply power to theliquid recovery mechanism 20 and to the second liquid recovery mechanism60 until the liquid 1 that remained on the substrate P and the liquid 1that was discharged from the liquid supply mechanism 10 (supply tube 15)without being recovered by the third liquid recovery mechanism 17 arecompletely recovered.

For example, based on the detection result of the liquid sensor 82arranged in the vicinity of the recovery nozzle 21 of the recovery tube24, the liquid recovery mechanism 20 is driven by the power suppliedfrom the back-up power source 102. Specifically, while the liquid sensor82 detects the liquid 1, the liquid 1 (that is, the liquid 1 present onthe substrate P) is recovered from the substrate P, so the liquidrecovery mechanism 20 continues the drive at least until the liquidsensor 82 does not detect the liquid 1. In the same manner, liquidsensors are arranged in the tube paths 68, 69 of the second liquidrecovery mechanism 60, and based on the detection result of the liquidsensors, the second liquid recovery mechanism 60 can be driven. In thiscase as well, the second liquid recovery mechanism 60 continues thedrive until the liquid sensor does not detect the liquid 1.

Furthermore, based on the detection result of the liquid sensor 81arranged in the vicinity of the supply nozzle 14, the third liquidrecovery mechanism 17 constituting an exhaust mechanism also can bedriven. For example, while the liquid sensor 81 detects the liquid 1,the liquid 1 is present in the supply tube 15, so the third liquidrecovery mechanism 17 continues the drive until the liquid sensor 81does not detect the liquid 1.

Alternatively, after the commercial power source 100 stops supplyingpower, information concerning the liquid amount to be discharged fromthe supply port of the supply nozzle 14 of the liquid supply mechanism10 is obtained in advance by, for example, experimentation, simulation,or the like, and the obtained information is stored in a memory deviceMRY. Based on the stored information, the liquid recovery mechanism 20,the second liquid recovery mechanism 60, and the third liquid recoverymechanism 17 can be driven. For example, after the commercial powersource 100 stops supplying power, after cutting off the liquid supplyflow path of the supply tube 15 by the valve 13, the liquid amount to berecovered by driving the third liquid recovery mechanism 17 can beobtained in advance based on the volume of the liquid supply flow pathof the supply tube 15. Furthermore, after the commercial power source100 stops supplying power, the liquid amount that still remains on thesubstrate P is substantially the same as the liquid amount of the liquidimmersion region AR2, and can be obtained in advance based on, forexample, the distance between the optical element 2 of the projectionoptical system PL and the substrate P and the area of the liquidimmersion region AR2. After the commercial power source 100 stopssupplying power, the information concerning the sum of the liquid amountthat still remains on the substrate P and the liquid amount that isdischarged from the supply tube 15 is stored in advance in the memorydevice MRY. After the commercial power source 100 stops supplying power,the liquid recovery mechanism 20 and the second liquid recoverymechanism 60 continue the recovery operation at least until the sum ofthe recovered liquid amount reaches the sum of the liquid amount storedin the memory device MRY.

Furthermore, after the commercial power source 100 stops supplyingpower, for example, the second liquid recovery mechanism 60 may be madeto have a greater rate of liquid recovery than before the power supplywas stopped. Specifically, the drive amount (drive force) of the vacuumsystem of the second liquid recovery mechanism 60 may be increased. Thedriving of the second liquid recovery mechanism (vacuum system) becomesa vibration source, so it is preferable that the drive force of thesecond liquid recovery mechanism decreases or stops during exposureprocessing. However, after the commercial power source 100 stopssupplying power, the exposure processing also stops. Therefore, byincreasing the drive force of the vacuum system when it is supplied withpower from the back-up power source 102, the second liquid recoverymechanism 60 suppresses leakage of the liquid 1 to the outside of thesubstrate stage PST (at least outward from the recovery port 61), orsuppresses the spread of leakage.

Additionally, when the commercial power source 100 is abnormal, there isa possibility that humidity and temperature of the chamber cannot becontrolled, and particularly the performance capability of theprojection optical system PL may be deteriorated. Because of this, thepower of the back-up power source 102 also can be supplied to devicescontrolling the atmosphere (humidity and temperature) of the chamber.Furthermore, when the commercial power source 100 is abnormal, the poweralso can be supplied to the chamber-controlling devices by using anotherback-up power source (third power source) different from the back-uppower source 102. In this case, a chamber can be divided into aplurality of regions, and the power also can be supplied to thedevice(s) controlling the chamber storing at least the projectionoptical system PL. By doing this, immediately after the commercial powersource 100 recovers, the exposure apparatus EX can be promptly operated,and the negative effects due to an abnormality of the commercial powersource 100 can be minimized. In addition, the power of the back-up powersource 102 also can be supplied to an undepicted local temperatureadjusting device in which the temperature of the projection opticalsystem PL is locally adjusted. In this case, it is acceptable to supplypower by the back-up power source 102 to the devices controlling thechamber atmosphere, and it also is acceptable not to do so.

Furthermore, it is not necessary to provide one back-up power source 102(and another back-up power source (third power source)) for eachexposure apparatus, because one back-up power source 102 can be usedwith a plurality of exposure apparatus. By doing this, the number ofback-up power sources 102 can be minimized, and the arrangement area ofthe exposure apparatus EX including the back-up power source 102 can beminimized.

As explained above, when the liquid recovery mechanism 20 (second liquidrecovery mechanism 60) is driven by the power that is supplied from thecommercial power source 100, even when the commercial power source 100stops supplying power, the power supply for the liquid recoverymechanisms 20, 60 is switched to the back-up power source 102.Accordingly, the liquid 1 that remains on the substrate P is recoveredby the liquid recovery mechanisms 20, 60 that are driven by the powerthat is supplied from the back-up power source 102, and liquid 1 is notleft on the substrate P. Therefore, out-flow of the liquid 1 can besuppressed, and occurrence of problems can be suppressed, such as theproblems of oxidation or failure of mechanical parts in the vicinity ofthe substrate stage PST that supports that substrate P, and changes inthe environment in which the substrate P is placed. Therefore, after thepower supply of the commercial power source 100 recovers, occurrence ofproblems can be suppressed, such as the problem of deterioration ofexposure precision due to the discharged liquid 1, and a device withhigh pattern precision can be manufactured.

In addition, by providing the liquid absorption member 62 on thesubstrate stage PST as the second liquid recovery mechanism 60, theliquid 1 can be reliably held (recovered) over a wide range. Inaddition, by connecting the vacuum system 70 to the liquid absorptionmember 62 via the flow path 63 and the tube path 68, the liquid 1absorbed to the liquid absorption member 62 is constantly discharged tothe outside of the substrate stage PST. Therefore, changes in theenvironment (atmosphere) in which the substrate P is placed can befurther reliably controlled, and weight fluctuation of the substratestage PST caused by the liquid 1 can be controlled. On the other hand,the liquid 1 recovered by the liquid absorption member 62 can be made toflow into the liquid recovery portion 73 due to gravity, withoutproviding the vacuum system 70. In addition, it is acceptable to nothave the vacuum system 70, the liquid recovery portion 73, etc., and tosimply arrange the liquid absorption member 62 on the substrate stagePST, and the liquid absorption member 62 that has absorbed the liquid 1can be regularly replaced (for example, for each lot). In this case, theweight of the substrate stage PST changes according to the amount ofabsorbed liquid 1, but stage positioning accuracy can be maintained bychanging the stage control parameters according to the weight of theliquid 1 recovered by the liquid absorption member 62.

In addition, instead of the third liquid recovery mechanism 17, apressure pump may be provided, and connected to the liquid supply flowpath of the supply tube 15 via the suction tube 18 (gas exhaust tube inthis case), and gas (air) can be discharged toward the supply nozzle 14from the position immediately after the downstream side of the valve 13.By doing this, after the commercial power source 100 stops supplyingpower, the liquid 1 stored in the liquid flow path in the supply tube 15on the downstream side of the valve 13 and in the supply nozzle 14 isdischarged onto the substrate P. The discharged liquid can be recoveredby the liquid recovery mechanism 20 and/or the second liquid recoverymechanism 60. Furthermore, in this case as well, the pressure pump canbe driven based on the information stored in the memory device MRY.

Additionally, it is acceptable to have another vacuum system differentfrom the vacuum system 25 that is normally used, and to connect theback-up power source 102 to this other vacuum system. In this case, ifthe suction force of the other vacuum system is set to be larger thanthe suction force of the vacuum system 25, the liquid 1 can be recoveredin a short period of time.

The following explains another embodiment with reference to FIG. 6. Thesame structural parts as described above are identified by the samesymbols, and the description thereof is simplified or omitted.

In FIG. 6, the exposure apparatus EX is provided with the liquid supplymechanism 10 having the supply tube 15 that supply the liquid 1 betweenthe projection optical system PL and the substrate P and the liquidrecovery mechanism 20 having the recovery tube 24 that recovers theliquid on the substrate P. Furthermore, the liquid supply mechanism 10is provided with the third liquid recovery mechanism 17 constituting asuction portion having the suction tube 18 that can draw the liquid 1.

The third liquid recovery mechanism 17 is provided with the samefunctions as the liquid recovery mechanism 20 and the second liquidrecovery mechanism 60, and is provided with a vacuum system 90 connectedto one end portion of the suction tube 18, a gas-liquid separator 92arranged in the suction tube 18, and a dryer 91 that dries the gasseparated by the gas-liquid separator 92. Furthermore, the liquid 1separated by the gas-liquid separator 92 is recovered by a liquidrecovery portion 94 via a recovery tube 93.

The liquid supply mechanism 10 is provided with a switching portion 19that switches the supply path of the supply tube 15 connected to theliquid supply portion 11 with the suction path of the suction tube 18connected to the vacuum system 90. In this embodiment, the switchingportion 19 includes a solenoid valve, and the supply tube 15 and thesuction tube 18 are connected to the switching portion 19, respectively.

In this embodiment, a tube member that forms a flow path connecting thevacuum system 90 and the switching portion 19 is called a “suction tube18”, and a tube member that forms a flow path connecting the liquidsupply portion 11 and the switching portion 19 is called a “supply tube15”. Furthermore, a tube member that forms a flow path connecting theswitching portion 19 and the liquid supply port 14A is called a “supplynozzle 14”.

When the operation of the switching portion 19 is controlled by thecontroller CONT and the switching portion 19 is connected to the supplytube 15, the supply port 14A of the supply nozzle 14 and the liquidsupply portion 11 are connected via the supply tube 15. At this point,the suction path of the suction tube 18 is cut off. Meanwhile, when theswitching portion 19 is connected to the suction tube 18, the supplyport 14A of the supply nozzle 14 and the vacuum system 90 of the thirdliquid recovery mechanism 17 are connected via the suction tube 18. Atthis time, the supply path of the supply tube 15 is cut off.Furthermore, there is a possibility that the switching portion 19becomes a heat source, so in order to suppress the deterioration ofexposure precision due to heat, it is preferable that the switchingportion 19 is arranged outside of the chamber that stores the exposureapparatus EX.

Furthermore, the switching portion 19 of this embodiment is a so-callednormally closed type that mechanically cuts off the supply path of thesupply tube 15 by using a spring or the like when an abnormality occurs,for example, when the drive source (commercial power source 100) of theexposure apparatus EX (controller CONT) stops due to a power outage.Additionally, in the switching portion 19 of this embodiment, when anabnormality occurs, the supply path of the supply tube 15 ismechanically closed, and the suction path of the suction tube 18 isopened by connecting the suction path of the suction tube 18.

A check valve 95 is arranged in the suction tube 18. In the suction tube18 connected to the switching portion 19 and the vacuum system 90, thecheck valve 95 is arranged between the switching portion 19 and thegas-liquid separator 92 and is arranged in a position close to theswitching portion 19. In the liquid 1 flowing into the suction tube 18,the check valve 95 suppresses the liquid 1 from flowing from the vacuumsystem 90 side to the switching portion 19 side.

The following explains an operation of the exposure apparatus EX havingthe above-mentioned structure with reference to the schematic view shownin FIG. 7.

When the substrate P supported by the substrate stage PST isliquid-immersion exposed, as shown in FIG. 7A, the controller CONTconnects the switching portion 19 to the supply tube 15 of the liquidsupply mechanism 10, and connects the liquid supply portion 11 and thesupply port 14A of the supply nozzle 14 via the supply tube 15. By doingthis, the liquid 1 sent from the liquid supply portion 11 is suppliedonto the substrate P via the supply tube 15, the switching portion 19,and the supply port 14A of the supply nozzle 14, and the liquidimmersion region AR2 is formed on the substrate P.

After the liquid immersion exposure of the substrate P is completed, inorder to recover the liquid 1 on the substrate P, the controller CONTstops sending (supplying) the liquid 1 from the liquid supply portion 11of the liquid supply mechanism 10, and the drive of the liquid recoverymechanism 20 and the second liquid recovery mechanism 60 is continuedfor a predetermined period of time. Furthermore, the controller CONT isconnected to the suction tube 18 by driving the switching portion 19,and closes the supply path of the supply tube 15 and opens the suctionpath of the suction tube 18. By doing this, as shown in FIG. 7B, theliquid 1 on the substrate P is recovered by the third recovery mechanism17. By doing this, while the liquid 1 is recovered after the exposure iscompleted, the liquid recovery mechanism 20, the second liquid recoverymechanism 60, and the third liquid recovery mechanism 17 are used, andthe liquid recovery operation is performed. Thus, the recovery operationof the liquid 1 can be effectively performed in a short period of time.

After the drive of the liquid recovery mechanism 20, the second liquidrecovery mechanism 60, and the third liquid recovery mechanism 17 iscontinued for a predetermined period of time, and the liquid 1 on thesubstrate P is recovered, the controller CONT stops the drive of theliquid recovery mechanism 20 and the second liquid recovery mechanism60. Meanwhile, even after the drive of the liquid recovery mechanism 20and the second liquid recovery mechanism 60 is stopped, connection ofthe switching portion 19 to the suction path of the suction tube 18 iscontinued, and the suction operation by the third liquid recoverymechanism 17 is continued.

The controller CONT moves the substrate stage PST to an unloadedposition in order to unload the substrate P from the substrate stage PSTas shown in FIG. 7C. At this time, the switching portion 19 is connectedto the suction path of the suction tube 18, and the supply port 14A ofthe supply nozzle 14 and the vacuum system 90 are connected via thesuction tube 18. Therefore, when liquid does not need to be supplied,such as when the liquid supply mechanism 10 does not supply the liquid 1after (or before) liquid immersion exposure is completed, the suctionoperation by the third liquid recovery mechanism 17 arranged in theliquid supply mechanism 10 is continued. Thus, the liquid 1 that stillremains within the flow path of the supply nozzle 14 and in the vicinityof the supply port 14A is recovered by the third liquid recoverymechanism 17. Because of this, when liquid does not need to be supplied,for example, the liquid supply mechanism 10 does not supply the liquid 1after (or before) liquid immersion exposure is completed, a problem issuppressed in which the liquid 1 that remains in the supply nozzle 14leaks (drips) onto the substrate P or the substrate stage PST, ormechanical parts in the vicinity of the substrate stage PST. Therefore,occurrence of a problem can be suppressed in which the leaked liquidcauses oxidation or failure of mechanical parts in the vicinity of thesubstrate stage.

Furthermore, the drive of the liquid recovery mechanism 20 and of thesecond liquid recovery mechanism 60 is stopped after being continued fora predetermined period of time, but the drive can be further continued.By doing this, even if the liquid 1 drips from the supply nozzle 14,etc., the liquid 1 can be recovered by the liquid recovery mechanism 20and the second liquid recovery mechanism 60.

Furthermore, during the liquid immersion exposure of the substrate P,when an abnormality occurs, for example, when the commercial powersource 100 stops supplying power, the normally closed type switchingportion 19 of the liquid supply mechanism 10 is operated, and the supplypath of the supply tube 15 is cut off. By doing this, a problem does notoccur in which the liquid 1 leaks onto the substrate P from the liquidsupply mechanism 10 after the commercial power source 100 stopssupplying power. Additionally, when the commercial power source 100stops supplying power, the switching portion 19 is operated andconnected to the suction path of the suction tube 18. The suction pathof the suction tube 18 is opened, and the supply port 14A of the supplynozzle 14 and the vacuum system 90 are connected via the suction tube18. Furthermore, when the commercial power source 100 stops supplyingpower, the back-up power source 102 supplies the power to the thirdliquid recovery mechanism 17. When the vacuum system 90 of the thirdliquid recovery mechanism 17 is operated by the power that is suppliedfrom the back-up power source 102, the liquid 1 that remains within thesupply nozzle 14 and in the vicinity of the supply port 14A is drawn bythe vacuum system 90 of the third liquid recovery mechanism 17 via thesuction tube 18. By doing this, after the commercial power source 100stops supplying power, a problem can be further reliably suppressed inwhich the liquid 1 leaks from the liquid supply mechanism 10 to thesubstrate P, and occurrence of a problem can be suppressed in which theliquid 1 splashes on the substrate stage PST and in the vicinity of thesubstrate stage PST.

As explained above, when the liquid supply mechanism 10 does not supplythe liquid 1, the liquid 1 is drawn by driving the third liquid recoverymechanism 17, and the liquid 1 that remains in the supply nozzle 14 ofthe liquid supply mechanism 10, etc. can be recovered; thus, a problemcan be suppressed, for example, in which the liquid 1 leaks from theliquid supply mechanism 10 when liquid does not need to be supplied.Therefore, occurrence of problems such as oxidation or failure ofmechanical parts in the vicinity of the substrate stage PST due to theleaked liquid 1 can be suppressed.

When an abnormality such as a power outage occurs, exposure isimpossible, and liquid does not need to be supplied. However, in thiscase as well, as the liquid 1 is recovered by the third liquid recoverymechanism 17, problems such as the liquid 1 leaking from the liquidsupply mechanism 10 after the power supply is stopped can be suppressed.

Additionally, in the suction tube 18, by having the check valve 95 thatsuppresses the liquid 1 from flowing into the switching portion 19 fromthe vacuum system 90 side, even when the vacuum system 90 cannot beoperated for some reason, a problem can be suppressed in which the drawnliquid 1 flows back onto the substrate P. In this case, by having thecheck valve 95 in a position close to the switching portion 19 andminimizing the volume of the suction path of the suction tube 18 betweenthe check valve 95 and the switching portion 19, even if the liquid 1flows back onto the substrate P, the volume of the liquid 1 can beminimized.

In addition, in this embodiment, after liquid immersion exposure iscompleted or when the commercial power source 100 stops supplying power,the switching portion 19 is operated. However, during the liquidimmersion exposure of the substrate P, if the liquid recovery mechanism20 cannot be operated for some reason and the liquid 1 on the substrateP is not recovered, by operating the switching portion 19, the liquid 1can be recovered by the third liquid recovery mechanism 17 of the liquidsupply mechanism 10. At this point, if the flow amount sensor that candetect the liquid recovery amount by the liquid recovery mechanism 20 isarranged, for example, in recovery tube 24, based on the detectionresult of the flow amount sensor, the operation status of the liquidrecovery mechanism 20 can be determined. Based on the detection resultof the flow amount sensor, when the controller CONT determines that theliquid recovery amount is less than or equal to a predetermined value,the liquid supply operation by the liquid supply portion 11 of theliquid supply mechanism 10 is stopped, and the liquid 1 is recovered bythe third liquid recovery mechanism 17 by operating the switchingportion 19. Thus, even when an abnormality occurs in the liquid recoveryoperation of the liquid recovery mechanism 20, by operating theswitching portion 19, the liquid 1 is recovered by the third liquidrecovery mechanism 17 of the liquid supply mechanism 10. Thus, splashingand leaking of the liquid 1 to the outside of the substrate P can besuppressed, and occurrence of a problem can be suppressed, for example,the problem of oxidation of mechanical parts and electric leakage ofelectronic devices (a drive device such as a linear motor that drivesthe substrate stage PST and a sensor such as a photo-multiplier).

When an abnormality of the positional relationship between the substratestage PST that supports the substrate P and the projection opticalsystem PL is detected, the liquid supply by the liquid supply mechanism10 is stopped, and the suction operation of the liquid 1 by the thirdliquid recovery mechanism 17 can be started. Here, the abnormalpositional relationship between the substrate stage PST and theprojection optical system PL is a state in which the liquid 1 cannot beheld under the projection optical system PL, and includes an abnormalpositional relationship in at least one of the Z axis direction and theXY direction.

That is, even if the operation of the liquid supply mechanism 10 and theliquid recovery mechanism 20 is normal, if an abnormality occurs in theoperation of the substrate stage PST, and the substrate stage PST isarranged in a position shifted in the XY direction (or Z direction)relative to a desired position with respect to the projection opticalsystem PL, the liquid immersion region AR2 of the liquid 1 cannot besuitably formed between the projection optical system PL and thesubstrate P supported by the substrate stage PST (the liquid 1 cannot beheld under the projection optical system PL). In this case, the liquid 1may leak to the outside of the substrate P and/or outside of thesubstrate stage PST, resulting in the liquid 1 getting on the movingmirrors 45 of the substrate stage PST. Then, the liquid recoverymechanism 20 cannot recover a predetermined amount of liquid 1, so thecontroller CONT detects that an abnormality occurs based on thedetection result of the flow amount sensor arranged in the recovery tube24, etc. When the abnormality is detected, the controller CONT operatesthe switching portion 19 and stops the liquid supply operation by theliquid supply mechanism 10, and the liquid 1 is recovered by using thethird liquid recovery mechanism 17 of the liquid supply mechanism 10.

Furthermore, in order to detect an abnormality of the positionalrelationship of the substrate stage PST with respect to the projectionoptical system PL, without using the detection result of the flow amountsensor arranged in the recovery tube 24, etc. of the liquid recoverymechanism 20, the position of the substrate stage PST in the XYdirection is detected by, for example, the interferometers 46, and basedon the position detection result, the abnormality of the positionalrelationship can be detected. The controller CONT compares the substratestage position detection result obtained by the interferometers 46 withthe allowable value that has been set in advance, and when the stageposition detection result of the interferometers 46 exceeds theallowable value, the supply operation of the liquid 1 can be stopped,and the operation of the switching portion 19 can be performed.Furthermore, the position of the substrate P in the Z axis direction isdetected by a focus detection system that detects the position of thesubstrate P surface in the Z axis direction, and the stage positiondetection result by the focus detection system is compared with a presetallowable value. When the detection result of the focus detection systemexceeds the allowable value, the controller CONT can stop the supplyoperation of the liquid 1 and perform the operation of the switchingportion 19. Thus, the controller CONT detects the abnormality of thepositional relationship between the projection optical system PL and thesubstrate stage PST, based on the detection result of the substratestage position detection device including the interferometers 46 and thefocus detection system, and when an abnormality is detected, the liquidsupply operation can be stopped, the switching portion 19 can beoperated, and the liquid 1 can be recovered by the third liquid recoverymechanism 17.

In this embodiment, an explanation was given in which the switchingportion 19 switches between the supply tube 15 and the suction tube 18,but a mode (stand-by mode) also can be used in which the switchingportion is not connected to either the supply tube 15 or the suctiontube 18. Here, the stand-by mode of the liquid supply mechanism 10includes a mode that does not perform either the supply or recovery ofthe liquid 1.

Meanwhile, the cross-sectional area of the supply path between thesupply port 14A and the switching portion 19 is determined based on thesurface tension of the liquid 1 (water in this embodiment). Byoptimizing the cross-sectional area of the supply path, based on thesurface tension of the liquid 1, when the liquid supply mechanism 10does not supply the liquid 1, a problem can be further suppressed inwhich the liquid 1 leaks (drips) from the supply port 14A. Specifically,when the liquid 1 remains in the supply path between the supply port 14Aand the switching portion 19, the cross-sectional area of the supplypath is determined to be such that the supply path is covered by thesurface tension of the liquid 1. That is, when the liquid 1 is storedwithin a supply path that is set to a cross-sectional area (innerdiameter) D1, as shown in the schematic view of FIG. 8A, when the liquid1 closes the supply path by surface tension of the liquid 1, thepressure difference, with respect to the liquid 1, between the switchingportion 19 side (vacuum system 90 side) of the supply path and thesupply port 14A side becomes large. Therefore, the liquid 1 is suitablyrecovered. However, when the surface tension of the liquid 1 (droplet)deteriorates, there is a possibility that a situation might occur inwhich the supply path cannot be closed, as shown in FIG. 8B. In thiscase, a problem occurs in which the liquid (droplet) 1 drips due to theweight (gravity effect) of the liquid 1, cannot be recovered by thethird liquid recovery mechanism 17, and leaks from the supply port 14A.Then, in order to recover the liquid (droplet) 1, the suction force(drive amount) of the third liquid recovery mechanism 17 needs to beincreased, and there will be an energy loss.

Therefore, in order to suitably recover the liquid 1 by the third liquidrecovery mechanism 17, based on the surface tension of the liquid 1, thecross-sectional area of the supply path is made small. FIG. 9A is aschematic view showing a state in which liquid 1 is stored in the supplypath having a cross-sectional area (inner diameter) D2 smaller than thecross-sectional area (inner diameter) D1. Even in the case of the liquid1 whose surface tension is low, by determining the cross-sectional areaof the supply path based on the surface tension of the liquid 1, asshown in FIG. 9A, the supply path can be closed by the liquid 1, wherebythe liquid 1 can be suitably recovered. Furthermore, as shown in theschematic view of FIG. 9B, in the supply path having a smallercross-sectional area D2, even if liquid (droplet) 1 still remains, thedroplet of the liquid 1 is sufficiently small, so there is no leakagefrom the supply port 14A caused by drips due to the weight of the liquid(gravity effect), and the droplet of the liquid 1 can be suitablyrecovered without increasing the suction force (drive force) of thethird liquid recovery mechanism 17.

Furthermore, an earthquake can be considered as an abnormality inaddition to the above situations. In this case, a vibration detector,such as an acceleration sensor, is provided in the main body of theexposure apparatus or in a location where the main body of the exposureapparatus is arranged. Based on the output of this acceleration sensor,the exposure operation including the liquid supply operation is stopped,and as described in the above embodiment, the liquid recovery operationby the liquid recovery mechanism and the temperature/humidity control bya chamber can be continued.

Furthermore, a P wave detector also can be used as a vibration detector,which detects a P wave, which is transmitted most quickly amongearthquake waves and felt as an initial vibration by human beings.

As described above, the liquid 1 of this embodiment is composed ofdistilled water. There are advantages that a large amount of distilledwater can be easily obtained at semiconductor manufacturing facilitiesand there are no negative effects on the photoresist on the substrate P,the optical elements (lens), etc. In addition, distilled water has nonegative effects on the environment, and the amount of containedimpurities is extremely low, so the operation also is expected in whichthe surface of the substrate P and the surface of the optical elementsprovided on the front end surface of the projection optical system PLare cleansed.

Furthermore, the index of refraction of distilled water (water) withrespect to the exposure light EL having a wavelength of approximately193 nm is about 1.44. Therefore, when the ArF excimer laser (wavelength:193 nm) is used as a light source of the exposure light EL, thewavelength at the substrate P is shortened to 1/n, that is, toapproximately 139 nm, and high resolution is obtained. In addition, thedepth of focus is increased by approximately n times compared to that ofair, that is, approximately 1.44 times. Thus, when it is sufficient tosecure a depth of focus that is approximately the same as when used inair, the numerical aperture of the projection optical system PL can beincreased, and the resolution increases because of this point as well.

Additionally, in this embodiment, a lens 2 is mounted on the front endof the projection optical system PL. The optical element mounted on thefront end of the projection optical system PL can be an optical plateused for adjusting the optical characteristics of the projection opticalsystem PL, such as aberration (spherical aberration, coma etc.).Instead, it may be a plane parallel plate that can transmit the exposurelight EL. Furthermore, when the pressure between the substrate P and theoptical element on the front end of the projection optical systemgenerated by the flow of the liquid 1 is large, instead of making theoptical element replaceable, the optical element may be rigidly fixed sothat it does not move due to the pressure.

In addition, the liquid 1 of this embodiment is water, but liquids otherthan water may be used. For example, if the light source of the exposurelight EL is an F₂ laser, the F₂ laser light is not transmitted in water.Thus, a liquid of a fluorine system, such as fluorine oil orperfluorinated polyether (PFPE), that can transmit the F₂ laser light,may be used as the liquid 1. Furthermore, as the liquid 1, a materialalso can be used that has transmissivity with respect to the exposurelight EL, has high index of refraction, and is stable with respect tothe projection optical system PL and the photoresist coated on thesubstrate P surface (for example, cedar oil).

In the above-described embodiment, an exposure apparatus is used inwhich liquid is locally filled between the projection optical system PLand the substrate P. However, this invention also can be used in aliquid immersion exposure apparatus in which a stage that holds asubstrate to be exposed is moved in a liquid tank, as disclosed inJapanese Laid-Open Patent Application 6-124873, or a liquid immersionexposure apparatus in which a liquid tank having a predetermined depthis formed on a stage and the substrate is held therein, as disclosed inJapanese Laid-Open Patent Application 10-303114.

In addition, not only a semiconductor wafer for manufacturing asemiconductor device, but also a glass substrate for a display device, aceramic wafer for a thin film magnetic head, and an original plate(synthetic quartz, silicon wafer) of a mask or reticle used in anexposure device can be the substrate P in each of the above-describedembodiments.

As the exposure apparatus EX, in addition to the scanning type exposureapparatus (scanning stepper) using a step-and-scan method that scans andexposes a pattern on the mask M by synchronously moving the mask M andthe substrate P, a projection exposure apparatus (stepper) using astep-and-repeat method in which the pattern on the mask M isbatch-exposed in a state where the mask M and the substrate P remainstationary, and the substrate P is sequentially step-moved, also can beused. Furthermore, this invention also can be used for an exposureapparatus using a step-and-stitch method in which at least two patternsare partially superimposingly transferred onto the substrate P.

As for the type of the exposure apparatus EX, this invention is notlimited to the exposure apparatus for manufacturing a semiconductorelement that exposes a semiconductor element pattern onto the substrateP. This invention also can be used for an exposure apparatus formanufacturing a liquid crystal display element for manufacturing adisplay, and an exposure apparatus for manufacturing a thin filmmagnetic head, an image pick-up element (CCD), or a reticle or mask, forexample.

Furthermore, this invention also can be applied to an exposure apparatusthat projects spot light by a projection optical system and forms apattern onto the substrate P without using the mask M.

Additionally, this invention also can be used for a twin stage typeexposure apparatus as disclosed in Japanese Laid-Open Patent ApplicationNos. 10-163099 and 10-214783, Published Japanese translation of PCTInternational Publication for Patent Application No. 2000-505958, etc.

When a linear motor is used for the substrate stage PST and/or the maskstage MST (see U.S. Pat. No. 5,623,853 and U.S. Pat. No. 5,528,118), anair floating type that uses an air bearing or a magnetic floating typethat uses Lorentz forces or reaction forces can be used. In addition,each of the stages PST and MST may be of a type that moves along aguide, or each may be of a guideless type that has no guides.

For the drive mechanism for each of the stages PST and MST, a flat motormay be used that drives each of the stages PST and MST using anelectromagnetic force by facing a magnetic unit, in which magnets aretwo-dimensionally arranged, and an armature unit in which a coil istwo-dimensionally arranged. In this case, either the magnetic unit orthe armature unit may be connected to the stages PST and MST, and theother of the magnetic unit or the armature unit may be provided on theside of the surface on which the stages PST and MST move.

As described in Japanese Laid-Open Patent Application 8-166475 (U.S.Pat. No. 5,528,118), the reaction force generated by the movement of thesubstrate stage PST may be mechanically released to the floor (ground),so as not to be transmitted to the projection optical system PL, byusing a frame member. As described in Japanese Laid-Open Application8-330224 (U.S. patent application Ser. No. 08/416,558), the reactionforce generated by the movement of the mask stage MST may bemechanically released to the floor (ground), so as not to be transmittedto the projection optical system PL, by using a frame member.

Instead of fixing the moving mirrors 45 to the substrate stage, forexample, a reflective surface can be formed on the end surface (sidesurface) of the Z stage (substrate holder) 51 by mirror finished surfaceprocessing. Furthermore, the auxiliary plate 43 was a convex portion,but when the substrate holder is embedded in the Z stage 51, theauxiliary plate 43 can be a concave portion. In addition, the substrateholder can be separate from the Z stage 51. Furthermore, the substrateholder can be a pin chuck type.

Furthermore, by arranging a normally closed valve in the recovery tubeof the liquid recovery mechanism 20, power from a back-up power sourceonly needs to be supplied to at least the vacuum system 70 of the vacuumsystems 70 and 74 when the main power supply is stopped.

The exposure apparatus of this embodiment is manufactured by assemblingthe various subsystems including each structural element in such a wayas to ensure specific mechanical precision, electrical precision, andoptical precision. In order to ensure these types of precision, afterand before the exposure apparatus is assembled, adjustments are made tothe various optical systems in order to achieve optical precision,adjustments are made to the various mechanical systems in order toachieve mechanical precision, and adjustments are made to the variouselectrical systems in order to achieve electrical precision. Theprocesses for assembling the various subsystems into the exposureapparatus include, for example, making mechanical connections,connecting cables for electric circuits, connecting ducts for pressurecircuits, and the like, between the various subsystems. Each of thesevarious subsystems, of course, has its own individual assembly processbefore the various subsystems are assembled into the exposure apparatus.Once the process by which the various subsystems are assembled into theexposure apparatus has been completed, overall adjustments are made inorder to secure the various types of precision in the exposure apparatusas a whole. Furthermore, it is preferable that the exposure apparatusshould be manufactured in a clean room in which the temperature,cleanliness, etc. are controlled.

As shown in FIG. 10, a micro device, such as a semiconductor device, ismanufactured via step 201 of designing a performance capability and afunction of the micro device, step 202 of manufacturing a mask (reticle)based on the designing step, step 203 of manufacturing a substrate thatis a base material of the device, substrate processing step 204 ofexposing a pattern of the mask onto the substrate by using the exposureapparatus EX of the above-described embodiment, device assembly step(including a dicing process, a bonding process, and a packaging process)205, testing step 206, etc.

Some aspects of this invention relate to an exposure apparatus thatexposes an image of a pattern onto a substrate by a projection opticalsystem, and that includes a liquid recovery mechanism that recoversliquid supplied to the substrate by using power that is supplied from afirst power source, and a second power source that supplies the power tothe liquid recovery mechanism at least when the first power source isabnormal.

Even when the power source is abnormal, for example, when the powersupply is stopped, flowing of liquid can be suppressed. Thus, occurrenceof a problem due to the discharged liquid can be suppressed.Furthermore, a problem also can be solved in which the liquid is leakedfrom the liquid supply mechanism when liquid does not need to besupplied. Therefore, a device with good pattern precision can bemanufactured, in which a pattern can be transferred onto a substratewith good precision.

While the invention has been described with reference to preferredembodiments thereof, it is to be understood that the invention is notlimited to the preferred embodiments or constructions. The invention isintended to cover various modifications and equivalent arrangements. Inaddition, while the various elements of the preferred embodiments areshown in various combinations and configurations, that are exemplary,other combinations and configurations, including more, less or only asingle element, are also within the spirit and scope of the invention.

What is claimed is:
 1. A liquid immersion exposure apparatus comprising:a projection system having a last optical element; a liquid supplysystem having a first path through which immersion liquid is supplied toa supply opening; and a liquid removal system having a second pathconnected to the first path, the liquid removal system removing theimmersion liquid from the first path using the second path so that thesupply flow path becomes a substantially gas filled space.
 2. Theapparatus according to claim 1, wherein the liquid removal systemconnects the first path to a vacuum system via the second path.
 3. Theapparatus according to claim 1, wherein the liquid removal systemsupplies a gas to the first path via the second path.
 4. The apparatusaccording to claim 3, wherein the immersion liquid in the first path isremoved from the supply opening by supplying the gas via the secondpath.